Aricept is proving to be an effective treatment for Alzheimer's disease

Researchers have produced compelling evidence of the positive impact of the Alzheimer's drug Aricept.

They have shown that patients who take the drug, technical name donepezil, are able to carry out everyday activities for much longer than other Alzheimer's patients.

US researchers carried out tests on 415 people with Alzheimer's. Some were given donepezil, and others a placebo.

Those who took donepezil were able to carry out everyday activities such as shopping for an average of five months longer than patients who took a placebo.

The researchers measured the amount of time before patients' functioning declined based on a clinical rating scale.

The lead researcher was Dr Richard Mohs, of the Mount Sinai School of Medicine and Bronx VA Medical Center in Bronx, New York.

He said: "For Alzheimer's patients and their families, five months can mean another birthday celebration or another holiday, and five months more that they can stay in their own homes."

Most studies of donepezil have looked at its effects on the way the brain works rather than level of functioning in daily activities.

Dr Mohs said: "This shows that in addition to helping people preserve their ability to learn new information and remember what they've learned, donepezil also helps preserve their ability to do the laundry and enjoy their hobbies - the things that help them stay independent and maintain their quality of life."

Second study

The results were echoed by a second separate study which found that Alzheimer's patients who took donepezil declined at about half the rate of those taking a placebo.

The one-year study involved 286 people in Scandinavia and the Netherlands.

Researcher Dr Bengt Winblad, of the Karolinska Institute, Alzheimer's Disease Research Center in Stockholm, Sweden, said: "These results show that donepezil is an effective treatment in the long-term and demonstrate the importance of continued donepezil treatment for optimal benefits in patients with mild to moderate Alzheimer's disease."